This invention relates to attachments to marine propulsion systems and more particularly to plates bolted to outboard motors to which remote control steering mechanisms are connected.
Outboard motors are marine propulsion devices adapted to be mounted on the transom of a boat for pivotal movement relative to the transom about a substantially vertical steering axis. The device includes a vertical drive shaft, a power head rotatably connected to the upper end of the drive shaft and a propeller assembly connected to the lower end of the drive shaft, all arranged as a pivotal unit to pivot about the steering axis aft of the transom mount. The rotating parts are sealed by water tight housings and seals with a rotating horizontal propeller shaft extending through a water seal to permit attachment of the propeller external to the sealed environment.
The steering axis is forward of the drive shaft. The attachment for mounting the device on the transom is connected to the vertical power train by a pivotal tilt axle that is transverse to the steering axis.
Small outboard motors are steered by a rigid handle extending forward of the drive shaft that may include a throttle for control by an operator seated at the motor.
It is more common, especially with larger motors, for the operator to be situated far forward of the one or more motors to be operated by a remote steering device that may include flexible cables or hydraulic cylinders actuated by a steering wheel at one end and attached at the other end by steering attachments to the pivotal unit either forward or aft of the steering axis. This invention is an improvement in the steering attachment to the motor.
With very large, high power, outboard motors the forces generated at the attachment are very great due to the thrust of the propellers and the high speeds in rough waters. It is usual practice to make the attachment at a point far back of the steering axis for greater leverage. This also gives better steering control because a given movement of the cable or cylinder produces a smaller angular change of direction. In the prior art, a horizontal plate was bolted to the motor, usually by sandwiching it between the housings of the upper power head and the drive shaft column using the bolts around the circumference. This is a threat to the water seals if done incorrectly and is labor intensive. The end of the steering cable or hydraulic cylinder is connected to the plate. The horizontal plate is vulnerable to vertical forces since it is only attached at its edge in only one plane.